Hormone Test
Anti-Müllerian Hormone (AMH)
A comprehensive guide to the Anti-Müllerian Hormone (AMH) test, the gold standard for evaluating ovarian reserve and predicting reproductive lifespan.
Test Overview
AMH is a protein hormone produced by granulosa cells in ovarian follicles. It indicates the size of the remaining egg supply.
Key Timing
Unlike FSH or LH, AMH levels remain relatively stable throughout the menstrual cycle. The test can be performed on any day of the month.
1. Purpose and Uses of the AMH Test
The AMH test is primarily used to assess a woman's "biological clock" and fertility potential.
Key Indications
- Evaluate Ovarian Reserve (quantity of remaining eggs).
- Predict the onset of menopause.
- Diagnose PCOS (Polycystic Ovary Syndrome), often indicated by high levels.
- Plan for IVF treatment to determine the likely response to ovarian stimulation medication.
- Monitor ovarian health after chemotherapy or surgery.
2. Procedure and Timing
This is a standard blood test. Because AMH is produced by small growing follicles (which are present constantly), the levels do not fluctuate significantly with the menstrual cycle.
Timing Advantage
While FSH and Estradiol must be tested on Day 2 or Day 3 of the cycle, AMH can be tested at any time. This makes it a convenient first step in fertility screening.
3. Understanding Ovarian Reserve
Women are born with their lifetime supply of eggs. As age progresses, this reserve diminishes.
- Production: AMH is produced by the microscopic follicles that contain immature eggs.
- Correlation: The more follicles you have (higher reserve), the more AMH is produced. Lower follicle counts result in lower AMH levels.
- Quality vs. Quantity: AMH measures the quantity of eggs remaining, but it does not measure the genetic quality of those eggs.
4. Normal Levels by Age
AMH levels naturally decline with age. Below are general reference ranges:
| Result Category | Range (ng/mL) | Interpretation |
|---|---|---|
| Very Low | < 0.5 ng/mL | Diminished reserve |
| Low | 0.5 – 1.0 ng/mL | Below average fertility |
| Normal | 1.0 – 3.5 ng/mL | Good fertility potential |
| High | > 3.5 ng/mL | High reserve or PCOS |
Age-Specific Averages
An AMH of 1.5 ng/mL might be concerning for a 25-year-old but excellent for a 42-year-old.
- Under 30: Typically > 2.5 ng/mL
- Age 30-35: Typically 1.5 – 2.5 ng/mL
- Age 35-40: Typically 1.0 – 1.5 ng/mL
- Over 40: Typically < 1.0 ng/mL
5. Interpreting Results
Low AMH (Diminished Reserve)
A low result indicates fewer remaining eggs. However, low AMH does not mean you cannot get pregnant naturally.
High AMH (PCOS Risk)
Very high levels (often > 4.0 or 5.0 ng/mL) indicate a strong likelihood of Polycystic Ovary Syndrome (PCOS).
6. AMH and IVF Success
AMH is the most critical number fertility specialists use to plan IVF treatment.
- Medication Dosing: Low AMH = higher dose needed. High AMH = lower dose to avoid OHSS.
- Egg Retrieval Predictions: Higher AMH usually correlates with more eggs retrieved.
A Note on Quality
A woman with "High AMH" at age 40 still faces age-related egg quality issues. A woman with "Low AMH" at age 28 may have fewer eggs, but they are likely high quality. Age remains the #1 predictor of egg quality.